title: Covalent immobilization of alpha-galactosidase from Penicillium griseoroseum and its application in oligosaccharides hydrolysis.
abstract: Partially purified alpha-Galactosidase from Penicillium griseoroseum was immobilized onto modified silica using glutaraldehyde linkages. The effective activity of immobilized enzyme was 33%. Free and immobilized alpha-galactosidase showed optimal activity at 45 degrees C and pH values of 5 and 4, respectively. Immobilized alpha-galactosidase was more stable at higher temperatures and pH values. Immobilized alpha-galactosidase from P. griseoroseum maintained 100% activity after 24 h of incubation at 40 degrees C, while free enzyme showed only 32% activity under the same incubation conditions. Defatted soybean flour was treated with free and immobilized alpha-galactosidase in batch reactors. After 8 h of incubation, stachyose was completely hydrolyzed in both treatments. After 8 h of incubation, 39% and 70% of raffinose was hydrolyzed with free and immobilized alpha-galactosidase respectively. Immobilized alpha-galactosidase was reutilized eight times without any decrease in its activity.
authors.affiliation: Departamento de Bioquimica e Biologia Molecular-BIOAGRO, Universidade Federal de Viçosa, Viçosa 36570.000 Minas Gerais, Brazil. dlfalkoski@yahoo.com.br
authors.forename: Daniel Luciano
authors.initials: DL
authors.lastname: Falkoski
authors.forename: Valéria Monteze
authors.initials: VM
authors.lastname: Guimarães
authors.forename: Marisa Vieira
authors.initials: MV
authors.lastname: de Queiroz
authors.forename: Elza Fernandes
authors.initials: EF
authors.lastname: de Araújo
authors.forename: Maíra Nicolau
authors.initials: MN
authors.lastname: de Almeida
authors.forename: Everaldo Gonçalves
authors.initials: EG
authors.lastname: de Barros
authors.forename: Sebastião Tavares
authors.initials: ST
authors.lastname: de Rezende
mesh_terms: D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009844:Oligosaccharides / Q000378:metabolism*; D010407:Penicillium / Q000201:enzymology*; D011887:Raffinose / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D000519:alpha-Galactosidase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004800:Enzymes, Immobilized; D009844:Oligosaccharides; D000519:alpha-Galactosidase; D011887:Raffinose